(1) Field of the Invention
This invention relates to an auxiliary lens system for a binocular telescope, in which auxiliary lens cylinders accommodating tele-or wide-conversion lenses for tele-or wide-converting the main lens system can be held in or away from the front of the objective lenses of the binocular telescope. More specifically, the invention concerns an auxiliary lens system for binocular telescope, which is provided with a role of auxiliary lenses for converting the focal distances in two stages to that of tele-or wide-conversion lenses without influencing the position of image obtained with the main lens system.
(2) Prior Art
A prior art binocular telescope, of either poroprism type or dahaprism type, is not provided with auxiliary lenses which can convert the focal distance in two stages without influencing the position of image obtained by the main lens system.
In other words, with the prior art binocular telescope only a telescopic image of a preset magnification can be obtained, and it is impossible to enjoy telescopic observation of tele-or wide-converted focused images of higher magnifications.